Method of forming explosive black powder into spherical grains.



P. I. 6: E. DU PONT.

APPLICATION FILED AUG.13 1913.

177' Off/YE X METHOD OF FORMING EXPLOSIVE BLACK POWDER INTO SPHERIGAL GRAINS.

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FRANCIS I. DU PONT AND ERNEST DU PONT, OF WILMINGTON, DELAWARE.

METHOD or FORMING Specification of Letters Patent.

EXPLOSIVE BLACK POWDER INTO SPHEBICAL GRAINS.

Patented Aug. 4, 1914..

To all whom it may concern:

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-Be it known that we, FRANCIS I. DU Porn and Banner on Pon'r, citizens of the United States, residing at \Vilmington, county of New Castle, and State of Delaware, have in-- vented a new and useful Improvement in Methods of Formin Explosive Black Powder into Spherical rains, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

The object of our invention is to manufacture black powder, in granular form, with greater economy, and in more nearly perfect shape, than heretofore.

The process embodying our invention comprises the following steps. The ordinary in gredients of which black powder is composed, for example, 73 parts of'niter, 16

parts of the mixture,but if the mixing 18 one at a lower temperature, more water can be used. The niter, charcoal and sulfur may be first incorporated and the water adde but it will be ordinarily preferable to in-' corporate the ingredients in the presence of water. The mass is then subdivided into particles of approximately uniform wei htor conveyed to, a revo vwhich has the effect of;

and dropped upon, ing heated surface,

shaping the'particles int-o balls or spheres tending to assume substantially perfect conr escape from the receptacle except through tour.

means of any particular apparatus; order that the process may means for executing the process, we herein disclosed an apparatus embodying such means, although the apparatus itself is hereby disclaimed as our joint invention.

In the drawings: vation of a portion of our apparatus adapted to carry out our process. Fig. 2 is a side view of the remaining portion of such apparatus (shown partly in end view in Fig. 1). Figs. 3 and 4 are enlarged detail views showing how the propeller blades in the plate.

' having a number of thoroughly mixed with l The process need not be carried out by but in: be better under- 5 stood, as well asfor the purpose of inform-Z ing those skilled in the art of a pracfiicali ave Figure 1 1s a side ele-v g fill the holes The explosive ingredients, in the form of a pasty mass by revious admixture with water as hereinbe ore explained, are introduced nto a conical receptacle or hopper a which is preferably steam-jacketed. \Vithin the receptacle a is a vertical revoluble shaft 1) radial propeller blades 0 more or less inclined to the vertical. Projecting inward from the walls of the receptacle a are a number of radial blades or wings d, which just clear the blades c. Thereby rotation of the mixture within the receptacle is prevented or obstructed and the same is forced down toward the open bottom of the receptacle. Any suitable means for rotating the shaft 7) may be employed, as, for instance, a driving shaft 6 having a bevel gear f in driving engagement with a bevel gear 9 on the shaft 6 On the extreme lower end of the shaft are inclined blades h, similar to the blades 0 but performing the special function of pressing the material through holes 2' in a fiat horizontall extending revoluble annular plate j, w ich is virtually the rim portion of a relatively large wheel j, rotatable on a vertical axis, and driven by means of a bevel gear .,wheel at engaging a rack n arranged on the lower face of the wheel in concentric relation to the wheels axis and between said axis and the rows of holes 2. The holes 2' are varranged in rows in concentric relation to the axis and to each other and extend entirely around the wheel near its periphery. I

The portion of the wheel which, at any given time, covers the outlet of the receptacle 1;, closes said outlet, so that no material can the holes i. The blades into the holes av similarly to the manner in which a nail hole is filled with putty by means of a knife, as may be clearly seen by reference to Fig. 3. The holes i extend completely through the plate 9" from face to face thereof, but the material is prevented h press the material from being forced out of the lower ends of the holes. by-means of a stationary plate or uard 0, which immediately underlies that part of. the wheel which, at any given time, is beneaththe outlet of the receptacle a.

At a suitable distance (measuring circumferentially along the rows of "holes in the wheel 7') from the mouth ofthe receptacle a (say 180 degrees therefrom) is arranged a wheel, or series of wheels, p, turning on a horizontal axis within a vertical plane extending radially of the axis of the wheel 7'.

.The wheel, or series of wheels, p, is of subsprocket wheel engages a sprocket chain. It

will thus be understood that the wheel 7) will be driven by reason of its engagement with the perforations in the wheel 7' and need not be otherwise positively driven. It will also be understood that the fingers g, as they are projected into the holes 2', necessarily push out the separate plugs ofpowder withwhich the holes have been filled.

Preferably the fingers are only of such length as to force the plugs to the lower edge of the holes but not to actually detach them from the wheel, to which they cling by reason of the pasty constituency of the material. To insure the complete detachment of the plugs there is provided a knock-off, preferably in the form of a thread t, arranged immediately below the wheel j and just in advance of the axis of the wheel p. To maintain the thread in a clean condition it is caused to pass from a spools to a spool 7', the latter being slowly rotated from any suitable driving means. The plugs thus detached from the wheel 7' fall down into a hopper v and thence pass into an inclined cylindrical vessel w. See F ig. 2. The wall of the vessel w, and also the wall of the hopper o and particularly the part of the latter upon which the pieces drop, must be heated and to this end are shown as steam-jacketed. The receiving end ofthewes'sel w is elevated above the level'a 'ofrthe dascharge end and is rotatably 'rollers w on a stand 9 the vessel w has e fI'Qm-LE two-armed spider zsecured low shaft 10 extend- 1ng axially 6f th ssel 'w. The shaft 10 turns in a bearingill and has secured to it a bevel gear 12, which engages any appropriate driving mechanis At the left hand side of Fig. 2 are shown a steam-inlet pipe 13 and a steam-discharge or drip-pipe 14, both connected to the steam jacket 15 in the wall of the hopper v. At the right hand side of Fig. 2 are shown pipes 16 and 17 performing similar functions. The inlet pipe 16 extends from 'the jacket 18 in the wall of the vessel w through one arm of the spider z and thence, through the hollow interior, and along the axis, of the shaft 10. The discharge pipe 17 extends from the jacket 18 through the other arm of the spider z and thence through the hollow interior of the shaft 10. The powder plugs discharged from the wheel m by the ejecting wheel p and the knock-off t are each in the shape of short cylinders. Preferably they are not, when ejected, in a substantially heated condition, and to enable them to cool somewhat after they are pressed into the holes 11, the ejecting means are arranged at a considerable distance from the outlet of the receptacle a. We have discovered-that when plugs of this shape, or of any irregu are dropped upon a heated surface lar shape, and agitated thereon, they tend to assume a practically perfect spherical form. When therefore, the powder grains are discharge from the lower end of the vessel to, they are j in the form of balls and spheres and are of uniform size.

If the material is especially stiff, the grains will less readily tend to assume a perfect spherical form, but even in this case a rounding of the edges will be effected with a resultant good product. It will be understood, therefore, that the process is not limited to one in which the resultant product necessarily approximates a spherical form.

The rolling of the grains or plugs upon ai heated surface not only rounds them as above described, but this rolling contact is maintained until they are thoroughly dry.

The apparatus also provides for a sufficient circulation of air to carry off the moisture,

which is expelled from the particles by means of the heat conducted and radiated from the heated surface.

By reason of the fact that the shaping and drying of the powder grains are entirely effected by the simple operation of conveying the grains to a heated moving surface, the

operation may be carried out on a large scale at a small expense. i

The mechanism herein set forth for carrying out the process is the subject matter of a separate patent a plication filed by the inventor, Francis I. u'Pont, one of the 'oint inventors of-the process forming the su ject -matter of this patent.

Having now fully described our invention, what we claim and desire to protect by Letters Patent isv 1. The process'of forming explosive powder into, grains whose shape tends to be spherical, which consists in. preparing the explosive in the form of a somewhat pasty mass, dividing the mass into separate parti cles, and simultaneously heating and agitating the same.

2. The process of forming explosive powder into grains whose shape tends to be spherical, which consists in preparin the explosive in the form of a pasty mass, ividing the mass into separate particles, and conveying the particles, to, and causing them to 1 vtroll upon, a heated surface.

3. The process of forming explosive pow der into grains whose shape tends to be sphericalawhich consists in preparing the explosive in the shape of a somewhat pasty mass, dividing the mass into separate particles of nonspherical shape and bringing the particles into moving contact with a heated surface.

at. The process of forming explosive powder into grains whose shape tends to be spherical which consists in preparing the explosive in the shape of a somewhat pasty mass, dividing the mass into separate cylindrically shaped particles and subjecting them to a rolling motion upon a heated surface.

5. Process of manufacturing black powder in the form of grains whose shape tends to be spherical, which consists in preparing an intimate mixture of Water and'of niter charcoal and sulfur in substantially the follow ing proportions: 73 parts of niter, 16 parts of charcoal and 11 parts of sulfur; dividing the mass into separate particles and bringing the separate particles into moving contact. with a heated surface.

6. Process of manufacturing explosive powder which consists in bringing the ingredients into a pasty condition by means of water, dividing the pasty mass into separate particles, rolling the particles upon a heated surface until they are rounded and continuing to roll them upon a heated surface until they are dry.

7. Process of manufacturing explosive powder which consists in bringing the ingredients into a pasty condition by means of Water, dividing the pasty mass into separate particles, rolling the particles upon a heated surface until they are rounded and continuing to roll them upon a heated surface until they are dry, while providing for sutlicient circulation of air to carry off the moisture which is being expelled from the particles by means of the heat conducted and radiated from the heated surface.

In testimony of which invention, we have hereunto set our hands, at Wilmington, on this 7th day of August, 1913.

rlaarzois i. DU PONT. ERNEST DU roar.

Witnesses J. Howsnn Gonnos, M. M. HAMILTON. 

